Nontraditional Materials and the Piano

Steve Brady, RPT

IN EXISTENCE FOR OVER 300 YEARS, the piano is considered as "traditional" a musical instrument as the violin or guitar. As with those instruments, we tend to think of the piano as being constructed from natural materials — wood, felt, leather, iron, brass — and indeed, the first pianos were made of just these things. From its beginnings as a mere subspecies of harpsichord, however, the gravicembalo col piano e forte has evolved into the modern grand piano, and in the process has changed dramatically in size, weight, sound, and the materials of its construction. Indeed, many of the materials used in pianos today were, at one time or another, considered "nontraditional," even experimental.

The first pianos were essentially harpsichords fitted with hammers that struck the strings, in place of the harpsichord's crow-quill plectra, which plucked them. The strings were made of metal — iron for the treble strings, brass or bronze for the bass — as were the tuning pins, bridge pins, hitch pins, nut pins, key pins, and various fasteners and levers. A small amount of wool cloth or felt served to quiet moving parts. The hammers on the first pianos had leather pads backed by wood or small rolls of parchment, and were attached to wooden shanks or stems. The remainder of the instrument would have been built of wood — cypress, pine, or spruce formed the soundboard and rim, while the pinblock, bridges, and hitch-pin rail were made of hardwoods such as hickory, beech, or maple. A century passed before this basic piano recipe began to change significantly.

Iron Bracing and Tempered Steel

Throughout the 18th century, the wire used in harpsichords and pianos would have been what today is called soft iron. In 1810, Pleyel of Paris patented the process of producing tempered steel wire, and its gradual introduction into pianos over the next 30 years may have constituted the first real step away from the original traditional materials used in pianos. Tempered steel wire could be strung at a higher tension than iron wire to produce the more powerful sound that was increasingly sought by musicians, and thus would have been viewed by many as an improvement over iron.

At about the time that tempered steel strings began appearing in pianos, so did iron bracing. Even with the lower-tensioned iron strings, the combined tension of all the strings on the structure of the piano was several thousand pounds — enough to cause the case of the instrument to eventually start coming apart. As early as 1800, there were a number of attempts to use iron tubes and bars, and iron hitch-pin plates, to brace the piano's structure against the tension of the strings. With the advent of tempered steel wire and the resulting general increase in string tensions, the search for an adequate bracing material took off in earnest. In 1825, Alpheus Babcock, a Boston piano maker, succeeded in having an iron piano frame cast in one piece for a square grand. By the end of the 19th century, virtually all piano makers had adopted this element, and today the one-piece, cast-iron plate is one of the signature features of the modern piano.

Leather vs. Felt Hammers

Piano hammer heads in the 18th-century English and Viennese schools of piano building were constructed of concentric layers of leather glued over a wooden molding. Leather was both flexible and firm, but came in many varieties of hardness or softness, which resulted in great varieties of tone quality. According to Rosamond E.M. Harding, in The Piano-Forte: Its History Traced to the Great Exhibition of 1851 (Heckscher, London, 1978), even as late as 1856 deer leather "was considered to be the most durable material for covering the hammer head; it would satisfy everyone if the skins were always of the best quality, of even thickness all over, and of even elasticity, which unfortunately was never the case." By then, experiments to find a more consistent hammer covering than leather had been going on for a long time, and the search included trials with cloth, cork, India rubber, sponge, and tinder. The first patent for felt-covered hammers was granted to Jean Henri Pape, of Paris, in 1826. For much of the second half of the 19th century, felt and leather were layered together in various configurations, but eventually felt — once a nontraditional material — became the new standard.